A solution of 0.142 g (0.5 mmole) of methyl azetidin-3-ylidene(3,5-difluorophenyl)acetate, 0.142 g (1 mmol) of 4-chloroacetophenone and 0.15 mL (12 mmol) of triethylamine in 5 mL of dichloroethane was stirred at room temperature. After 5 min, 0.422 g (2 mmol) of sodium triacetoxyborohydride was added and the mixture was stirred at room temperature for 3 h. The reaction was quenched by addition of saturated KHCO3 solution and the mixture was partitioned between 10 mL ether and 2 mL saturated KHCO3 solution. The layers were separated and the organic layer was dried over Na2SO4, and concentrated. The residue was purified by reverse phase chromatography (Waters Xterra C18, 19 mm×10 mm) using a gradient of CH3CN—H2O-Et3N (20:80:0.1 to 60:40:0.1) to afford the title compound; Mass Spectrum: m/e=378 (M+1 35Cl) and 380 (M+1 35Cl).
